Vehicular rack and pinion steering systems include an elongated flat gear or rack having teeth which mesh with mating teeth of a rotating pinion gear. The pinion gear is mounted on an end of a steering shaft. As a steering angle is imparted to the steering shaft, e.g., via rotation of a steering wheel, the pinion gear rolls along the rack, which in turn moves the rack in a corresponding steering direction. Tie rods are disposed at the distal ends of the rack. The tie rods ultimately connect to the front road wheels of a vehicle via a corresponding steering arm. Therefore, a rack and pinion steering system effectively converts rotational motion of a steering wheel into linear motion suitable for steering the vehicle, while also providing a suitable level of gear reduction.
Due to manufacturing tolerances and/or gear wear, impingement may result in the meshing gears of the rack and pinion portion of a manual steering gear. A transient stick-slip condition known as “stiction” may result. Transient stiction during execution of a steering maneuver can affect steering precision and feel, particularly in electronic power-assisted steering systems imparting steering assist along the steering column. However, the transient nature of the stiction condition makes such a condition difficult to properly isolate, diagnose, and correct.